A power supply control circuit can be coupled to or included as a portion of a power supply. The power supply can include a direct-current-to-direct-current (DC-DC) converter, and the control circuit can control the converter to provide a regulated output. Generally, the regulated output includes a specified output voltage including specified ripple or noise characteristics. Such output parameters are generally specified over a wide range of conditions including temperature and load. The regulated output can include a specified maximum output current or output power. A variety of topologies can be used to implement regulation, such as can include linear or switched-mode circuits. The power supply control circuit can implement a regulation law using one or more of voltage-mode or current-mode feedback. In one approach, a power controller can include a current limiting circuit. The current limiting circuit can sense one or more of input or output current and can control the behavior of the power controller to limit one or more of the input or output current.